1. Field of the Invention
The present invention relates to a navigation apparatus, a communication base station, a navigation system and a navigation method for guiding a moving body, such as, for example, an individual or an automobile to a destination, and in particular to a navigation apparatus, a communication base station, a navigation system and a navigation method using voice for guiding a moving body to a destination.
2. Description of the Related Art
Conventionally, a navigation system is widely used as means for guiding a moving body to a destination. A representative navigation system is a car navigation apparatus mounted on an automobile. An increasing number of car navigation systems include a voice guiding function for safety, in addition to a liquid crystal display for displaying a map to allow the user to visually confirm a route to a destination.
A car navigation apparatus includes a liquid crystal display for the user to visually confirm a route to a destination combined with a recording medium for storing map information (for example, a CD-ROM or DVD). This involves a problem of increasing the cost of such displays and recording media thus preventing use of the car navigation apparatus by a larger population.
As a solution to this problem, voice navigation systems have been proposed. For example, Japanese Laid-Open Publication No. 9-319991 discloses a navigation system which accesses various databases provided in a base station through communication means and notifies the user of the obtained information through a voice synthesis function of a cellular phone, so as to guide the user to a destination by dialog with the user. Such a guiding system, which can be implemented using a generally used cellular phone, requires no specific device and is thus inexpensive. This guiding system also provides a high level of safety since the guidance is performed through voice and does not require the user to confirm map information on a display screen.
However, such a conventional navigation system requires the user to communication with a base station in the form of dialog until the user arrives at the destination, and is not practical in terms of telephone charges to the user of the cellular phone. This system also requires the user to inform the base station of the current location of the user. This also prevents the user, who is driving the automobile, from concentrating on driving and thus is quite dangerous.
According to an aspect of the invention, a navigation apparatus for guiding a moving body from a current location to a destination using a communication base station includes a current location detection device for detecting a current location of the moving body and outputting current location information representing the current location; a sending device for sending the current location information and destination information representing a destination of the moving body to the communication base station via a communication line; a receiving device for receiving guiding information, which is required to guide the moving body from the current location to the destination and includes information representing a location of a guiding point and a navigation message corresponding to the guiding point, from the communication base station via the communication line; a memory device for storing the guiding information received by the receiving device; and a voice processing device for outputting the navigation message corresponding to the guiding point in voice format, based on the current location information output by the current location detection device and the information representing the location of the guiding point which is included in the guiding information stored in the memory device.
In one embodiment of the invention, the voice output from the voice processing device is one of a voice synthesized by a voice synthesis device and a voice of a specific individual user which is stored in the memory device in advance.
In one embodiment of the invention, the navigation apparatus is one of a cellular phone and a mobile information terminal.
In one embodiment of the invention, the information representing the location of the guiding point includes information representing a latitude and a longitude of the guiding point.
In one embodiment of the invention, the navigation message is one of text information and compressed voice information.
In one embodiment of the invention, the memory device further stores history information representing a history of a destination designated in the past.
In one embodiment of the invention, the memory device is a rewritable nonvolatile memory.
In one embodiment of the invention, the voice processing device compares the current location information and the information representing the location of the guiding point included in the guiding information so as to determine whether the moving body has passed the guiding point or not; when the moving body is determined to have passed the guiding point, the voice processing device determines an operation mode of the navigation apparatus; and when the operation mode is determined to be a mode other than the guiding mode, the voice processing device notifies a user of the navigation apparatus to switch the operation mode to the guiding mode in the voice format.
According to another aspect of the invention, a communication base station includes a map information database storing map information; a receiving device for receiving current location information representing a current location of a moving body and destination information from a navigation apparatus via a communication line; a search device for searching through the map information database based on the current location information and the destination information received by the receiving device, so as to acquire guiding information, which is required to guide the moving body from the current location to the destination and includes information representing a location of a guiding point and a navigation message corresponding to the guiding point; and a sending device for sending the guiding information to the navigation apparatus via the communication line.
In one embodiment of the invention, the communication base station further includes a category database storing information classified by category. The search device searches the category database, so as to acquire information representing at least one candidate for the destination and calculate a distance or a time to each candidate of the at least one candidate from the current location. The sending device sends the information representing the at least one candidate and information representing the distance or the time to the navigation apparatus via the communication line.
According to still another aspect of the invention, a navigation system for guiding a moving body from a current location to a destination is provided. The navigation system includes a navigation apparatus and a communication base station. The navigation apparatus includes a current location detection device for detecting a current location of the moving body and outputting current location information representing the current location; a first sending device for sending the current location information and destination information representing a destination of the moving body via a communication line to the communication base station; a first receiving device for receiving guiding information, which is required to guide the moving body from the current location to the destination and includes information representing a location of a guiding point and a navigation message corresponding to the guiding point, from the communication base station via the communication line; a memory device for storing the guiding information received by the first receiving device; and a voice processing device for outputting the navigation message corresponding to the guiding point in voice format, based on the current location information output by the current location detection device and the information representing the location of the guiding point which is included in the guiding information stored in the memory device. The communication base station includes a map information database storing map information; a second receiving device for receiving the current location information and the destination information from the navigation apparatus via the communication line; a search device for searching through the map information database based on the current location information and the destination information received by the second receiving device, so as to acquire the guiding information; and a second sending device for sending the guiding information to the navigation apparatus via the communication line.
According to still another aspect of the invention, a navigation method for guiding a moving body from a current location to a destination, using a navigation system including a navigation apparatus and a communication base station is provided. The navigation apparatus includes a current location detection device for detecting a current location of the moving body and outputting current location information representing the current location, and a memory device. The communication base station includes a map information database storing map information. The navigation method includes the steps of the navigation apparatus sending the current location information and destination information representing a destination of the moving body via a communication line to the communication base station; the communication base station searching through the map information database based on the current location information and the destination information, so as to acquire guiding information, which is required to guide the moving body from the current location to the destination and includes information representing a location of a guiding point and a navigation message corresponding to the guiding point; the communication base station sending the guiding information to the navigation apparatus via the communication line; the navigation apparatus storing the guiding information sent from the communication base station in the memory device; and the navigation apparatus outputting the navigation message corresponding to the guiding point in voice format, based on the current location information output by the current location detection device and the information representing the location of the guiding point which is included in the guiding information stored in the memory device.
In one embodiment of the invention, the communication base station further includes a category database storing information classified by category. The navigation method includes the steps of the communication base station searching the category database, so as to acquire information representing at least one candidate for the destination and calculate a distance or a time to each candidate of the at least one candidate from the current location; and the communication base station sending the information representing the at least one candidate and information representing the distance or the time to the navigation apparatus via the communication line.
According to still another aspect of the invention, the memory device further stores history information representing a history of a destination designated in the past. The communication base station refers to the history information stored in the memory device, and searches the category database in consideration of contents of the history information.
In one embodiment of the invention, the navigation method further includes the steps of the navigation apparatus comparing the current location information and the information representing the location of the guiding point included in the guiding information so as to determine whether or not the moving body has passed the guiding point; when the moving body is determined to have passed the guiding point, the navigation apparatus determining an operation mode of the navigation apparatus; and when the operation mode is determined to be a mode other than the guiding mode, the navigation apparatus notifying a user of the navigation apparatus to switch the operation mode to the guiding mode in the voice format.
Thus, the invention described herein makes possible the advantages of providing a navigation apparatus, a communication base station, a navigation system and a navigation method for guiding a user at a specific point so as to allow a user to reach a destination at a lower cost while guaranteeing safety.
These and other advantages of the present invention will become apparent to those skilled in the art upon reading and understanding the following detailed description with reference to the accompanying figures.